In vitro resistance of Neisseria gonorrhoeae to metronidazole.

Susceptibility of 64 clinical isolates of Neisseria gonorrhoeae to metronidazole was determined by the agar dilution technique using Mueller-Hinton and chocolate agar media. All isolates were resistant to metronidazole at 12.5 mug/ml in either medium. This lack of activity of metronidazole against N. gonorrhoeae would suggest that the ability to recover N. gonorrhoeae in patients being treated with metronidazole for concurrent Trichomonas vaginalis infections should not be hampered.